Currently, expensive radiation detectors are required to detect ambient radiation. These radiation detectors are constructed using Geiger-Mueller tubes. These tubes are quite fragile, and thus are easily broken. Moreover, the radiation detectors are relatively large and consume a large magnitude of power. Therefore, the detectors are not portable.
In the world of integrated circuits (ICs), transistors have sizes in the sub-micron range. Such small transistors are more sensitive to cosmic (neutrons) and alpha particle strikes. Consequently, particle hits to the silicon on which the transistors are fabricated can literally change the state of the transistor. For example, a latch holding a 0 value may be changed to a 1 value. This phenomenon is referred to as soft error.